User can delete preselected tags even when control is disabled

[mrchief]

Describe the bug
If you initialize the tree with pre-checked values and set disabled=true, the control still lets users remove the tags.

To Reproduce

• Go to https://dowjones.github.io/react-dropdown-tree-select/#/story/options
• Select disabled checkbox
• Click on x on the preselected tag

Expected behavior
The control should not allow deletions.

Screenshots

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[mrchief]

Still an issue!

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.